Roll changer and method for carrying out a flying roll change

ABSTRACT

A reel changer is used to support rolls of material. A web of the material is unwound from one of the rolls while an additional roll of material is held for use in a roll changer when the first roll is exhausted. The rolls are each supported for rotation by two holding fixtures. Each of these holding fixtures has a supporting journal with gripping jaws. At least four collets are arranged in an axial direction of the supporting journals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is the U.S. National Phase, under 35 USC 371, of PCT/EP 2004/052176, filed Sep. 15, 2004; published as WO 2005/054101 A2 on Jun. 16, 2005, and claiming priority to DE 103 56 028.9, filed Dec. 1, 2003 and to DE 20 2004 005 645.3 filed Apr. 8, 2004, the disclosures of which are expressly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is directed to roll changers and to methods for performing a flying roll change A roll changer for supplying a web of material has at least two receivers. One of these supports an unwinding web of material. The other supports a fresh roll for use in a flying roll change.

BACKGROUND OF THE INVENTION

Roll changers are typically employed in printing presses and are used for supplying the web of material used as the material which is to be imprinted. In this case, paper webs are typically used as the material. The web of material is initially wound on a roll of material and rolls off this roll of material.

So that upon the depletion of a roll of material, the entire printing press need not be stopped, it is generally known to perform a so-called flying roll change. For this purpose, a new roll of material, on whose outer layer of material appropriate gluing spots, for use in accomplishing a connection with the web of the roll of material which is running out, have, for example, been prepared, is placed into the roll changer. During of the flying roll change, the fresh web of material is then accelerated to a circumferential speed corresponding to the web speed of the established roll of material. In the course of the actual web change, the start of the web of the fresh roll of material is connected with the web of material on the roll of material which is running out, and the web of material on the roll of material which is running out is cut at substantially the same time. In this way, the start of the web of the fresh web of material is drawn into the printing press by the old web of material and a stoppage of the press is avoided.

Depending on the remaining thickness of the web of material on the roll of material which is running out, and in particular depending on the web's width and the tube core diameter, the web of material running out has a continuously changing inherently critical resonating number of revolutions.

With relatively large web widths, and in particular, with web widths of, for example, >3,600 mm, and with very high web draw-off speeds, such as, for example, with web draw-off speeds of 15 m/s, critical vibration conditions can arise in the web of material which is running off when the remaining web gets below a defined remaining thickness, because of vibration excitations in the range of the inherently critical resonating number of revolutions. To prevent these critical vibrating conditions, it is often necessary to reduce the web speed when the remaining thickness of the web falls below a minimum. Such application cases result in that either the web of material cannot be completely used, in order to prevent such critical vibrating conditions, or that the web draw-off speed must be reduced during the roll change. Printing costs are increased in an undesired way by both steps.

FR 2 076 474 shows a single receiver for rolls of material. Two rows of clamping jaws are arranged one behind the other.

DE 36 27 533 A1 describes a roll carrier. A support is placed against an unwound roll.

DE 100 56 274 A1 discloses a mandrel with two rows of clamping jaws which are arranged one behind the other. The diameter of the one row can be changed from 150 to 160 mm, and the diameter of the other row can be changed from 70 to 80 mm.

Devices for unwinding rolls are known from EP 0 441 152 A2, EP 0 708 047 A1 and EP 0 413 890 A1. Each of these has support journals with movable clamping jaws.

U.S. Pat. No. 3,891,158, U.S. Pat. No. 5,360,502, U.S. Pat. No. 5,316,230, U.S. Pat. No. 3,836,089 and U.S. Pat. No. 4,100,012 describe methods for roll changing.

SUMMARY OF THE INVENTION

The object of the present invention is directed to providing roll changers and to providing methods for performing a flying roll change.

In accordance with the present invention, the object is attained by the provision of a roll changer for supplying a web of material. The roll changer includes receivers which support at least one unwinding web of material and at least one fresh web of material. The fresh web of material is in a roll that has been prepared for a flying roll change. Both rolls of the webs of material are rotatably supported in the roll changer. Each roll is held by two receivers. Each such receiver has a support journal with clamping jaws.

The present invention is based on the basic premise of reducing the freely vibrating length of the unwinding roll of material. This is done in order to influence the inherently critical resonating number of revolutions of the unwinding roll of material in the desired way.

In the course of the employment of the roll changer in accordance with the present invention, a reduction of the freely vibrating length between the clamping points of the web of material being unwound at the roll changer takes place. A support device is provided, which support device is brought into engagement with the circumferential surface of the unwinding roll of material. It is possible, in accordance with the present invention, to considerably reduce the freely vibrating length by the use of this additional support of the roll of material between the clamping points. If, for example, the support device is brought into engagement with the circumferential surface of the unwinding roll of material exactly in the center of the roll between the clamping points, the vibrating length is halved in this way, and the inherently critical resonating number of revolutions is correspondingly displaced upwardly. In this case, the support device is arranged in such a way that it can be brought to rest against the circumferential surface of the unwinding roll of material when the unwinding roll of material is arranged in the position which is provided for the flying roll change. The critical vibrating conditions of the unwinding roll of material occur, in particular, shortly before the depletion of the web of material with the depleting roll having a relatively small thickness of web material remaining. A support of the unwinding roll is thus required, in particular, in the phase of the unwinding operation which immediately precedes the roll change.

The specific way in which the support device is configured is somewhat arbitrary, as long as a sufficient support of the unwinding roll of material is assured, for use in reducing the vibrating length. In accordance with a preferred embodiment of the present invention, the support device has at least one revolving support belt, which belt can be pressed against the circumferential surface of the unwinding roll of material. This support belt can be seated on rollers, for example, and will rotate at a speed which corresponds to the circumferential speed of the unwinding roll of material.

Depending on the type of application to which the roll changer is subjected, it can be useful to greatly reduce the freely vibrating length. This can be achieved because several of these support devices can be provided, and which several support devices come to rest against the circumferential surface of the unwinding roll of material side-by-side and spaced apart from each other. In that case, the freely vibrating length corresponds only to the respective distance between two adjoining ones of the support devices, or to the distance of the first support device, or of the last support device, from the clamping points of the unwinding roll of material. As a result, it is thus possible to change the freely vibrating length of the unwinding roll of material in any arbitrary manner.

The support device can be provided in a manner which is particularly simply if the support device does not have its own drive mechanism. In this case, the support device can itself be driven by the unwinding roll of material by the transfer of frictional forces. To the extent that such frictional forces are employed for driving the support device, the support device should preferably be produced from a wear-resistant material with a large coefficient of friction in the area of a contact face of the support device with the roll of material.

Alternatively, it is also within the scope of the present invention for a drive mechanism to be provided on the support device, by the use of which drive mechanism, the support device is being driven. For example, an electric motor can be provided for this usage, by the use of which electric motor one of the bearing rollers for seating the support belt is driven. By an appropriate control of the drive mechanism, it becomes possible, prior to bringing the support into contact with the roll of material, to accelerate the support to a speed which is synchronized with the circumferential speed of the roll of material. In this case, it is possible to avoid the occurance of an undesired slippage between the support device and the circumferential surface of the unwinding roll of material, or to avoid the formation of breaks in the material web, when the support belt is placed against the roll of material.

In many cases, the employment of the support device is desired only during defined phases of the operation of the roll changer, and in particular during the phase directly prior to the flying roll change. For this reason, it is particularly advantageous if the support device is seated so that it is movable between at least two functional positions. The first functional position corresponds to the actual position of employment or use, in which the support roller comes into contact with the circumferential surface of the unwinding roll of material and appropriately supports the roll of material. The second functional position corresponds to a position of rest, in which the support device is not in contact with the unwinding roll of material.

The specific manner in which the support device is attached or is supported, in relation to the roll changer, can basically be accomplished in any arbitrary manner. In accordance with a first embodiment of the present invention, the support device is fastened on the roll stand of the roll changer. This has the advantage that the support device will be moved along when the roll stand is pivoted. There is thus no relative movement between the support device and the appropriately assigned roll of material when the roll support is pivoted. With this embodiment, it is, in particular, possible that the support device can be brought to rest against the unwinding roll of material prior to the roll of material being arranged in the position that is required for a flying roll change. The unwinding roll of material is thereby also supported by the support device in the course of the pivoting of the roll stand, and is also preferably supported prior to the web of material being accelerated from a stop. Contact with the support belt takes place simultaneously.

To accomplish this preferred embodiment of the present invention, the support device can be fastened between two support arms of the roll stand. The two support arms also support the appropriately assigned roll of material.

Alternatively to this first preferred embodiment, the support device can also be fastened on a base that is located underneath the position of the unwinding roll of material which is intended for a flying roll change. As a result, the support device is not an integral component of the roll changer. This embodiment is of particular advantage if the support device is able to be lowered into the base. In its position of rest, in which the support device has been lowered into the base, the support device does not constitute an obstacle.

In order to be able, if necessary, to control or to regulate the support process of the unwinding roll of material by the employment of the support device, at least one sensor which is usable for measuring a support parameter, such as, for example, the actually expended support force, or the belt tension of the support belt, can be provided. A cooperatively provided control device, or a correspondingly employed control circuit, can process the results of the measurement provided by the sensor and can control, or can regulate, the support device in accordance with a predetermined desired value.

The employment of the support device in accordance with the present invention offers particularly significant advantages in connection with its use with roll changers in which rolls of material of a width of greater than or equal to 3,600 mm are processed. Webs of material of such widths are used, in particular, in connection with rotogravure imprinting in rotary rotogravure printing presses. The high printing speeds used in such rotogravure printing lead to the previously mentioned problems with inherently critical resonating numbers of revolutions.

In accordance with the method of the present invention, for operating the novel roll changer, the support device is brought to rest against the unwinding roll of material prior to the arrangement of the unwinding roll of material into a position that is suitable for a flying roll change. In the course of a pivoting of the roll stand, for arranging the unwinding roll of material in a position that is suitable for a flying roll change, the support device remains in engagement with the unwinding roll of material. This assures that the unwinding roll of material is also supported during the pivoting process of the roll stand. As soon as the roll stand has reached an end position, in which the unwinding roll of material takes up a position that is suitable for a flying roll change, the support device will remain in engagement with the unwinding roll of material until the flying roll change has been completed and the old roll of material can then be appropriately braked.

A support device can be provided for usage other than for the reduction of the freely vibrating length, or preferably in connection with it. The prevention of inherently critical resonating numbers of revolutions can also be improved because the freely vibrating length of the unwinding roll of material can be reduced by the use of longer mandrels.

To allow the longer mandrels to provide a sufficient clamping force on a contact face with the interior circumference of the core of the unwinding roll of material, it is proposed that at least two clamping jaws be arranged, one behind the other, on the mandrel and extending parallel with the axis of rotation of the support journal. Because of this increase in the number of the clamping jaws it is possible to apply a great clamping force. Accordingly, in addition to the reduction of the clamping length, the quality of the clamping is also increased by increasing the clamping rigidity such as by an increase of the clamping factor, or the chuck factor.

In the absence of a central support, paper widths of more than 4,000 mm, and in particular of 4,300 mm, and cores/sleeves of a diameter of 150 mm, do not allow the accomplishment of a dependable roll change at speeds of webs of material of more than 15 m/s when using the cores which presently are customary in the industry. Without the use of a support, and with such long sleeves it is possible to attain speeds of the web of material of maximally 12 m/s.

In the present invention, several clamping jaws, which adjoin each other in a row of clamping jaws, and which are, in particular, evenly spaced from each other, are preferably distributed over the circumference of the support journal. In a preferred embodiment of the present invention, two rows of clamping jaws are arranged on the mandrel in the axial direction of the mandrel, each row having eight clamping jaws which are arranged in the circumferential direction. This results in highly secure clamping of the roll of material on the mandrel.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention are represented in the drawings and will be described in greater detail in what follows.

Shown are in:

FIG. 1, a first preferred embodiment of a roll changer, in accordance with the present invention, with a support device, in a side elevation view, in

FIG. 2, a second preferred embodiment of a roll changer with a support device in a side elevation view, in

FIG. 3, a perspective view of a mandrel in the subject invention, in

FIG. 4, a support journal in cross section, in

FIG. 5, a cross section through a roll of material supported by support journals, in

FIG. 6, a schematic side elevation view of a scissors-type lifting platform with a fresh roll of material, in

FIG. 7, a schematic side elevation view of a scissors-type lifting platform with a support device on an unwinding roll of material, and in

FIG. 8, a schematic side elevation view of athe roll changer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first preferred embodiment of a roll changer 01 for use in feeding in a web 02 of material, and in particular for use in feeding a paper web, to a printing press, which is not specifically represented, is schematically represented in FIG. 1. A roll stand 04, which can be pivoted around a pivot shaft 03, and which is formed by two support arms, that are located one behind the other in the drawing plane, is provided on the roll changer 01. Receivers 05, such as, for example, mandrels 05, which are located opposite each other, are fastened on the free ends of the two support arms of the roll stand 04. Rolls 06, 07 of material can be clamped to the roll changer 01 between these receivers or mandrels 05.

In the process state represented in FIG. 1, an unwinding roll 06 of material and a fresh roll 07 of material, which fresh roll 07 has been prepared for a flying roll change, are clamped on the roll changer 01. The roll stand 04 had previously been pivoted into the position represented in FIG. 1, so that the unwinding roll 06 of material now takes up a position that is required for the flying roll change. A support belt 08 is pressed against the circumference of the fresh roll 07 of material from below the fresh roll 07, and is used for supporting the fresh roll 07 of material and for transmitting the driving forces, such as acceleration and braked stop in the loading position.

As soon as the roll stand 04 has been moved into the position represented in FIG. 1, for preparing a flying roll change, a support device 11, which has been fastened to a base 09, and which is located underneath the unwinding roll 06 of material, is moved upward until a support belt 12, seated on rollers 13, comes to rest against the circumference of the unwinding roll 06 of material. Pneumatic actuating cylinders 14 are provided for moving the support device 11 into the engaged position depicted in FIG. 1. The support belt 12 of the support device 11 is synchronized in speed with the paper web speed by the use of a frequency-regulated rotary current motor, which is not specifically represented. Tears in the web 02, when contact is made between the support belt 12 and the web 02, are prevented in this way by this speed synchronization.

The freely vibrating length of the unwinding roll 06 of material, which is the distance between the receivers 05, is shortened because of the contact pressure of the support belt 12 against the circumference of the unwinding roll 06 of material. The inherently critical resonating number of revolutions of the roll 06 of material is displaced into a non-critical range of the number of revolutions by this length shortening.

A second preferred embodiment of a roll changer 16, in accordance with the present invention, is represented in FIG. 2. A web 02 of material, the pivot shaft 03, the roll stand 04, the receivers 05, the unwinding roll 06 of material, the fresh roll 07 of material, and a support belt 08 for use in the support and the transmission of the drive forces of the fresh roll 07 of material can be seen in the second embodiment of the roll changer 16.

In contrast to the first embodiment of the roll changer 01 depicted in FIG. 1, in the second embodiment, two support devices 17 and 18 are provided on the roll changer 16, which two support devices are assigned to the left or to the right clamping position on the roll stand 04, respectively. As indicated on the left support device 17, by the use of dashed lines, the support devices 17 and 18 can be displaced in linear guides 19. In this way, the support devices 17, 18 can be matched to the changing diameter of the rolls 06, 07 of material, and can track them.

Support belts 22 are provided on the respective support devices 17 and 18. These support belts 22 can be brought into contact with the circumference of the roll 06, 07 of material to be supported. Pneumatic actuating cylinders 21 are provided for use in bringing the support belts 22 into and out of contact. By extension and retraction of these pneumatic actuating cylinders, the seating structure of the support belts 22 can be moved or pivoted.

The following actions are taken prior to a flying roll change being performed by the roll changer 16 shown in FIG. 2. Initially, an unwinding roll 06 of material is still in the so-called unwinding position on the right side of the pivot shaft 03, in a configuration of the roll changer which is not specifically represented. In this unwinding position, the unwinding roll 06 of material is unwound during the continuing printing process until the roll 06 of material falls below a defined roll diameter, resulting in a defined remaining web layer thickness. After the roll diameter falls below this predetermined remaining thickness, the actuating cylinder 22 is extended and the support belt 22 is brought into contact with the circumference of the roll 06 of material. The inherently critical resonating number of revolutions of the roll 06 of material is displaced into a non-critical range of a number of revolutions by this added support, so that the roll 06 of material can continue to be drawn off at an unchanged speed.

As soon as the unwinding roll 06 of material has been unwound down to a remaining thickness, which makes a roll change inevitable, the unwinding roll 06 of material is pivoted into the position where it is located to the left of the pivot shaft 03. This is done by pivoting the roll stand 04 and results in the orientation represented in FIG. 2. The support belt 22 continues to rest against the circumference of the unwinding roll 06 of material even during the pivot movement, and thus supports the unwinding roll 6 in this way.

After the unwinding roll 06 of material has reached the gluing position, or loading position, to the left of the pivot shaft 03, as represented in FIG. 2, a fresh roll 07 of material, which has been prepared for the roll change, is clamped in the roll changer 16. A flying roll change between the unwinding roll 06 of material and the fresh roll 07 of material can then be performed in a generally known manner. A reduction in the draw-off speed of web 02 of material is not necessary here. This is because a critical resonating number of revolutions of the unwinding roll 06 of material is displaced into the non-critical range by the employment of the support device 17.

The support device 17, 18 can be placed against the fresh roll 07 of material, while it is still stopped, and therefore rests against it during acceleration. Accordingly the support device 17, 18 can be embodied without a drive motor.

FIG. 3 depicts a receiver 05, which may be provided, for example, in the form of a mandrel 05, in the roll changers 01 or 16. A support journal 24 is provided on the mandrel 05, and has an exterior circumference which comes to rest against, and to engage an interior circumference of a core 10, such as, for example, a cardboard core 10 of a roll of material 06, 07, as seen in FIG. 5. To accomplish a connection, which is fixed against relative rotation between the roll 06, 07 and the mandrels 05, by means of a non-positive and positive connection, a plurality of clamping jaws 26, with at least four such clamping jaws 26, are provided on the support journal 24 in the circumferential direction of the support journal 24. Since the support journals 24 have a large insertion depth into the core 10 because of which, the freely resonating length between the clamping points can be reduced, at least two clamping jaws 26 are arranged one behind the other in the direction of the longitudinal axis of the support journal 24, i.e. in the axial direction of the support journals 24. These axially spaced clamping jaws 26 are aligned with each other, as seen in FIG. 3. Several clamping jaws 26, which are adjoining each other, are distributed over the circumference of the support journal 24, and are preferably evenly spaced. The clamping jaws 26, which are arranged circumferentially and axially next to each other, form ring-shaped rows 27 or 28 of clamping jaws, each with eight clamping jaws 26. The support journal 24 of the mandrel 05 depicted in FIG. 3 has an exterior diameter D24 of approximately 150 mm, as seen in FIG. 4.

A support journal 24 of a mandrel 05 is represented in cross section in FIG. 4. A length l24 of the support journal 24 in the axial direction of the support journal 24 is at least 250 mm. Lengths l24 of the support journals 24 of at least 300 mm, and in particular, of at least 330 mm, are also advantageous. A length l26 of each of the clamping jaws 26, in the axial direction of the support journals 24 is at least 80 mm, and in particular is at least 95 mm. In the axial direction of the support journals 24, the sum of the lengths l26 of the clamping jaws 26 is at least 300 mm, and in particular is 340 mm. In a further preferred embodiment, the sum of the lengths l26 of the clamping jaws 26 is 380 mm. A diameter D24 of the support journal 24 is greater than 140 mm. This diameter D24 lies, in particular, between 145 mm and 155 mm. A diameter D24 of the support journal 24 between 148 mm and 152 mm is particularly advantageous.

FIG. 5 shows a roll 06, 07 of material resting in, and supported by, both receivers or mandrels 05 and having a roll core 10, such as is preferably put to use in the above-described roll changer.

A length l10 of the core 10 of the roll 06, 07 of material, which is resting on, and which is held by the clamping jaws 26 of the support journal 24, is more than 4000 mm, and in particular is more than 4200 mm. A wall thickness b10 of the core 10 is more than 10 mm, and in particular, it is greater than 15 mm. A core wall thickness b10 of more than 17 mm, and in particular one which is greater than 20 mm, is particularly advantageous. An interior diameter d10 of the core 10 is 150.2±0.2 mm.

Alternatively to, or in concert with the steps for reducing the free clamping length of the roll of material, a determination of the web speed and/or of the diameter of the leftover roll during a flying roll change can take place for performing the flying roll change.

As previously described, a first web of material 02 of an unwinding roll of material 06 to be changed, which runs at a first web speed, is connected with a second web 29 of material of a fresh roll 07 of material, which second web 29 runs at a second web speed, during the flying roll change. Prior to connecting the first web 02 of material with the second web 29 of material, the first web speed is reduced to a second web speed, so that during the connecting process, the first web 02 of material has the second web speed.

It is also possible, prior to the connection of the webs 02, 29 of material, to determine a minimum diameter of the unwinding, soon to be leftover roll 06, as a function of a width b02 of the web 02, 29 of material, which determines at what time the two webs 02, 29 of material must be connected with each other at the latest.

In another preferred embodiment of the present invention, the second web speed, which is set during the connection, is determined as a function of the properties of the material of the core 10 of a roll 06, 07 of material.

In other preferred embodiments, geometric dimensions regarding the core 10 of the roll 06 of material, such as, for example, the size of the interior diameter d10 of the core 10, or the wall thickness b10 of the core 10, determine the reduced web speed of the first roll 02 of material during the connection.

In a further preferred embodiment, the second web speed, which is preset for the connecting process, is fixed by the geometric dimensions of the receiver 05, and in particular by the geometric dimensions of the support journal 24. It is also possible to fix the reduced web speed as a function of the length l26 of the clamping jaws 26 of the support journal 26.

The reduction of the web speed, together with the connecting process, is controlled by a program.

Equipping the roll stand 04 with the fresh roll 07 of material, and removing the depleting roll 06, takes place with the aid of a pushcart 31, such as, for example, a scissors-type lifting platform 31, as represented in FIGS. 6 and 7, respectively. Wheels 33 have been attached to the pushcart 31, by the use of which wheels 33, a horizontal movement of the pushcart 31 is possible. A movement in the vertical direction is also possible. A support device 11, with a support belt 12, which support device 11 is pivotably attached to the scissors-type lifting platform 31, is arranged on the pushcart 31. This support device 11 is substantially the same as the previously described support device 11. The support device 11 is motor driven, such as, for example, by the use of an a.c. motor, which motor accelerates the support belt 12, 22 of the support device 11 to the web speed and then, during removal of the depleted roll, places it against the depleted roll 06 of material by hydraulic means. Braking of the depleted web 02 of material is also aided by this motor, since the motor of the support device 11, together with the shaft motor of the roll stand 04, performs braking along the same torque curve until the roll 06 of now leftover material comes to a stop.

The new roll 07 of material is transported to the roll changer 01 by a transport cart 32 that is pulled by a chain. There, the transport cart 32 with the roll 06 of material stored on it, enters the lifting platform 31 on the level ground. Wheels 34 have been attached to the transport cart 32, by the use of which wheels 34, a movement of the transport cart 32 inside the scissors-type lifting platform 31 is made possible. The scissors-type lifting platform 31 moves into a centered position and lifts the new roll 07 of material to approximately 1600 mm above ground level. Thereafter, the center roll 07 of material is brought into the position in which it is placed on the shaft of the roll stand 04. When the position for placement on the shaft has been reached, the signal “advance sleeve” is issued to the roll stand 04. The receivers 05 with the support journals 24 are moved into the new roll 07 of material. Once the receivers 05 with the support journals 24 have been inserted into the new roll 07 of material and the clamping jaws 26 have been spread open, the scissors-type lifting platform 31 is lowered by issuing the signal “roll placed on shaft” and is moved into its base position.

In the course of the roll change, following the roll revolution, the support device 11 moves against the unwinding, depleted roll 06 of material and stabilizes it in its center. In response to the command “advance cutter” the unwinding web 02 of material is cut off the depleted roll 06 of material and is stopped by means of the shaft motor of the roll stand 04. As already previously described, the stopping process of the depleted roll 06 of material is aided by the support device 11 of the scissors-type lifting platform 31. The support belt 12 is pivoted away, and the scissors-type lifting platform 31 moves into its loading position for loading a fresh roll 07 of material.

In the meantime, as seen in FIG. 8 the core 10 of the depleted roll 06 with the leftover material, is removed by a spent core crane, and in particular by a clamping crane with a trolley and is conveyed into a cart for recycling.

A schematic plan view of the roll changer, with various stages of roll supply, is represented in FIG. 8.

While preferred embodiments of a roll changer and a method for carrying out a flying roll change, in accordance with the present invention are set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the specific type of web of material, the drive motors and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims. 

1-59. (canceled)
 60. A roll changer for supplying a web of material comprising: a roll stand adapted to rotatably support at least an unwinding web of material and a fresh web of material prepared for a roll changer; a first pair of spaced receivers on said roll stand and usable to rotatably support said unwinding web of material; a second pair of spaced receivers on said roll stand and usable to rotatably support said fresh web of material; a support journal on each said receiver; and a plurality of clamping jaws on each said support journal.
 61. The roll changer of claim 60 wherein at least four of said clamping jaws are arranged in an axial direction of each said support journal, each said clamping jaw having an axial length of at least 80 mm.
 62. The roll changer of claim 60 wherein a length of each said support journal in an axial direction is at least 250 mm, and a diameter of each said support journal is greater than 140 mm.
 63. The roll changer of claim 60 wherein a sum of axial lengths of said plurality of clamping jaws is at least 300 mm.
 64. The roll changer of claim 60 wherein each said support journal has at least two of said clamping jaws arranged one after another in an axial direction of said support journal and aligned circumferentially.
 65. The roll changer of claim 64 wherein at least four clamping jaws are arranged in said axial direction of said support journals in each said receiver.
 66. The roll changer of claim 60 wherein an axial length of each said support journal is at least 250 mm.
 67. The roll changer of claim 60 wherein each said support journal has at least two of said clamping jaws arranged in an axial direction of each said support journal.
 68. The roll changer of claim 60 wherein a length of each said support journal in an axial direction is at least 300 mm.
 69. The roll changer of claim 60 wherein a length of each said support journal in an axial direction is at least 330 mm.
 70. The roll changer of claim 60 wherein a length of each said clamping jaw in an axial direction of each said support journal is at least 95 mm.
 71. The roll changer of claim 63 wherein said sum of said axial lengths is at least 340 mm.
 72. The roll changer of claim 63 wherein said sum of said axial lengths is at least 380 mm.
 73. The roll changer of claim 60 wherein several of said clamping jaws on each said support journal are adjoining each other in a circumferentially extending clamping jaws row.
 74. The roll changer of claim 73 further including at least first and second circumferentially extending clamping jaw rows.
 75. The roll changer of claim 60 further including a roll core supporting each said web of material, said clamping jaws being received in said roll core.
 76. The roll changer of claim 75 wherein a length of each said core is greater than 4000 mm.
 77. The roll changer of claim 75 wherein a length of each said core is greater than 4200 mm.
 78. The roll changer of claim 75 further including a core wall thickness greater than 10 mm.
 79. The roll changer of claim 75 further including a core wall thickness greater than 15 mm.
 80. The roll changer of claim 75 further including a core wall thickness greater than 17 mm.
 81. The roll changer of claim 75 further including a core wall thickness greater than 20 mm.
 82. The roll changer of claim 75 further including a core interior diameter between 150.0 and 150.4 mm.
 83. The roll changer of claim 60 wherein said web of material is pulled off said unwinding web of material and further wherein said roll changer is usable to perform a flying roll changer.
 84. The roll changer of claim 60 wherein a diameter of each said support journal is greater than 140 mm.
 85. The roll changer of claim 60 wherein a diameter of each said support journal is between 145 mm and 155 mm.
 86. The roll changer of claim 60 wherein a diameter of each said support journal is between 148 mm and 152 mm.
 87. The roll changer of claim 83 further including a support device adapted to engage a circumferential surface of said unwinding web of material.
 88. The roll changer of claim 87 wherein said support device includes at least one support belt following a circulating path and being pressed against said circumferential surface of said unwinding web of material.
 89. The roll changer of claim 88 wherein said support belt is supported by rollers defining said circulating path.
 90. The roll changer of claim 87 further including a plurality of said support devices arranged side-by-side on said roll changer.
 91. The roll changer of claim 87 wherein said support device is driven by said unwinding web of material by friction.
 92. The roll changer of claim 87 further including a support device drive motor adapted to drive said support device.
 93. The roll changer of claim 92 wherein said support device drive motor is an electric motor.
 94. The roll device of claim 87 wherein said unwinding web of material has a circumferential speed and further wherein said support device is driven at a speed synchronized with said unwinding web circumferential speed.
 95. The roll changer of claim 87 wherein said support device is movable between at least first and second functional positions, when in said first functional position said support device engages said circumferential surface of said unwinding web of material and wherein said second functional position said support device is out of contact with said circumferential surface of said unwinding web of material.
 96. The roll changer of claim 87 wherein said support device is fastened on said roll stand of said roll changer.
 97. The roll changer of claim 96 wherein said roll stand is pivotable and includes first and second lateral support arms, at least one of said support devices being fastened between said first and second lateral support arms.
 98. The roll changer of claim 87 wherein said roll stand includes a base, said support device being fastened to said base below said unwinding web of material.
 99. The roll changer of claim 98 wherein said support device is lowerable into said base.
 100. The roll changer of claim 87 further including a support process parameter sensor on said support.
 101. The roll changer of claim 60 wherein said roll changer is arranged before, in a direction of web travel, a rotary rotogravure printing press.
 102. A method of operating a roll changer for supplying a web of material including: providing a roll stand; using said roll stand for supporting at least an unwinding web of material and a fresh web of material usable in a flying roll change; supporting said roll stand for pivotable movement between a first functional position and a second functional position; providing a support device; placing said support device against a circumferential surface of said unwinding web of material in said first functional position; pivoting said roll stand into said second functional position suitable for said flying roll change; and performing said flying roll change.
 103. A method of operating a roll changer for performing a flying roll change, including: providing a first, exhausting web of material of a roll of material to be changed; providing a second, fresh web of material of a roll of material; unwinding said first web of material at a first web speed; reducing said first web speed to a second web speed less than said first web speed; and connecting said first web and said second web at said reduced web speed.
 104. A method of operating a roll changer for performing a flying roll change, including: providing a first, exhausting web of material of a roll of material to be changed; providing a second, fresh web of material of a roll of material; unwinding said first web of material at a first web speed; determining a minimum diameter of said exhausting web of material roll using a width of said web of material; and connecting said first web to said second web when said minimum diameter is reached.
 105. A method for performing a flying roll change including: providing a first web of material in a first roll of material to be changed; providing a second fresh web of material in a second roll; rotating said first roll of material at a first web speed; reducing said first web speed of said first roll of material to a second, lower first roll of material speed; connecting said first web of material to said second web of material at said lower speed; supporting said first web of material on a first web core; and determining said second lower speed of said first roll of material as a function of properties of said first web core.
 106. The method of claim 103 further including fixing a minimum diameter of a leftover roll of said first web of material as a function of said first web speed and maintaining said minimum diameter during said connecting of said first web and said second web.
 107. The method of claim 103 further including fixing a minimum diameter of a leftover roll of said first web of material as a function of a width of said web of material prior to connecting said first web and said second web.
 108. The method of claim 104 further including reducing said first web speed to a second web speed less than said first web speed and connecting said first web and said second web at said reduced web speed.
 109. The method of claim 103 further including controlling said reducing of said first web speed to said second web speed using a program.
 110. The method of claim 103 further including determining a width of said first web of material and selecting said second web speed as a function of said width of said first web of material.
 111. The method of claim 103 further including providing a core of said roll of material to be changed, determining properties of a material constituting said core and determining said second web speed of said first material as a function of said properties.
 112. The method of claim 103 further including providing a core of said roll of material to be changed, determining geometric dimensions of a material constituting said core and determining said second web speed of said first material as a function of said geometric dimensions.
 113. The method of claim 112 further including selecting an inner diameter of said core as said geometric dimension.
 114. The method of claim 112 further including selecting a wall thickness of said core as said geometric dimension.
 115. The method of claim 103 further including providing a receiver of said roll changer, determining geometric dimensions of said receiver of said roll changer, using said receiver for receiving said first exhausting web of material of said roll of material and determining said second web speed as a function of said geometric dimensions of said receiver.
 116. The method of claim 115 further including providing clamping jaws having clamping jaw lengths in said receiver and using said clamping jaw lengths as said geometric dimensions of said receiver. 